Millions around the world, probably billions, have seen Rogue One: A Star Wars Story now. It’s already pulled in over $573 million at the worldwide box office, and it’s going to take in a bunch more as we head into January. However, not everything regarding Rogue One has been praiseworthy. In fact, there’s one element of the Star Wars spin-off that has been rather controversial and discussed extensively.

Rogue One features the resurrection of the late actor Peter Cushing as Imperial officer Grand Moff Tarkin, thanks to the magic of motion-capture performance and visual effects. For some it was a distraction that didn’t quite do the trick, but others weren’t even aware that the character was a digital recreation of a deceased actor. Today we have official details on how this came to be and what Lucasfilm intended to do if they couldn’t adequately recreate Grand Moff Tarkin in Rogue One.

Grand Moff Tarkin isn’t a huge part of Rogue One, but he does have a few key scenes as a rival to Director Orson Krennic (Ben Mendelsohn). While it might have been easier to have another actor step into the role, Industrial Light & Magic thought they could digitally recreate Peter Cushing rather than recasting, and Lucasfilm decided to let them have a shot.

First, Lucasfilm and Industrial Light & Magic obtained the permission of Peter Cushing’s estate. That makes the use of a dead man’s likeness in a film like this a little less ethically questionable, but that’s a discussion that we’ll be diving into in much more depth later this week.

In Rogue One, Tarkin is played by Guy Henry, best known for playing Minister of Magic Pius Thicknesse in Harry Potter and the Deathly Hallows Part I. He performed motion-capture on set and provided the voice as well. But what if the visual effects didn’t work?

John Knoll, the chief creative officer at Industrial Light & Magic and a visual effects supervisor on Rogue One (who also happens to share a story credit on the film with writer Gary Whitta), explains that they considered having Tarkin appear by hologram so that the visual effects didn’t have to be quite as realistic due to the grainy, warped nature of a hologram’s appearance in the Star Wars universe. Another option was just giving his dialogue to other characters.

However, in the end, it was determined that having Grand Moff Tarkin be more prominent in the movie was needed. Kiri Hart, a Lucasfilm story development executive and Rogue One co-producer told The New York Times:

“If he’s not in the movie, we’re going to have to explain why he’s not in the movie. This is kind of his thing.”

Indeed, Tarkin is very much in charge of the Death Star when we meet him in A New Hope, and Rogue One explains just how that came to be, showing that he was eager to take over the project from Director Orson Krennic. If Tarkin wasn’t there, it would have seemed odd that he was so adamant about not leaving when it seemed like the Death Star was on the verge of being destroyed.

There’s much more to discuss regarding the revival of Grand Moff Tarkin in this fashion, and we’ll dive more into that later this week, so stay tuned.